1. Field of the Invention
The present invention relates generally to an operation mode selecting device for washing machines incorporating a microcomputer-based control circuit, and more particularly to such a device wherein operation modes of the washing machine are selected with switches provided on an operation panel thereof.
2. Description of the Prior Art
In the following description, a step refers to each of wash, rinse and water discharge operations and an operation course refers to combination of the aforesaid steps performed in a cycle of operation of the washing machine.
For example, prior art twin-tub washing machine incorporates a microcomputer-based control circuit and the steps of wash, rinse and so on are controlled on accordance with an operation course set in the control circuit with control process selecting switches. The control process selecting switches include a water stream mode selecting switch for setting strength of water stream in the wash and rinse modes, a wash mode selecting switch for selecting one of time periods of wash operation and a rinse mode selecting switch for selecting the number of the rinse operation times. Additionally, on the operation panel are provided a clear switch for clearing the selected operation course and a start switch for starting the selected operation course after the selection thereof, the start switch also serving for momentarily interrupting execution of the selected operation course.
Data of a plurality of water stream modes in which strength of water stream differs from one another, data of a plurality of wash modes which provide different control processes from one another and data of a plurality of rinse modes which provide different control processes from one another are stored at the microcomputer. The water stream modes include "STANDARD", "INTENSE," "MILD" and "GENTLE." The "STANDARD" water stream mode is suitable for the washing and rinsing of clothes having standard degree of soil, the "INTENSE" water stream mode for the washing and rinsing of the clothes extremely soiled, the "MILD" water stream mode for the washing and rinsing of the clothes slightly soiled and the "GENTLE" water stream mode for the washing and rinsing of the clothes damaged easily. The "STANDARD" water stream mode is automatically selected when the control circuit is initialized and the water stream mode is then changed from "STANDARD" to "INTENSE," "MILD," "GENTLE" and "STANDARD" in turn in accordance with the number of operation times of the water stream mode selecting switch.
The wash modes are based on execution time period of the washing operation and include "TEN MINUTES," "SEVEN MINUTES," "FIVE MINUTES," "TWO MINUTES," FIFTEEN MINUTES" and "TWELVE MINUTES." The "TEN MINUTES" wash mode is automatically selected when the control circuit is initialized. The wash mode is changed from "TEN MINUTES" to "SEVEN MINUTES," "FIVE MINUTES," "TWO MINUTES," "FIFTEEN MINUTES" and "TEN MINUTES" in turn in accordance with the number of operation times of the wash mode selecting switch.
The rinse modes are based on two manners of rinse operation, that is, an overflow rinse and a water reserve rinse, and the numbers of rinse operation times. A "STANDARD" rinse mode is suitable for the rinsing of the clothes containing average amount of detergent. An "ECONOMY" rinse mode is suitable for the rinsing of the clothes containing small amount of detergent. A "GENTLE" rinse mode is suitable for the rinsing of the clothes damaged easily. A "CAREFUL" rinse mode is suitable for the rinsing of the clothes containing a large amount of detergent. The "STANDARD" rinse mode is selected when the control circuit is initialized. The rinse mode is changed from "STANDARD" to "ECONOMY," "GENTLE," "CAREFUL" and "STANDARD" in turn in accordance with the number of operation times of the rinse mode selecting switch.
The operation course including steps selected with the water stream mode selecting switch, the wash mode selecting switch and the rinse mode selecting switch is started when the start switch is turned on.
In the overflow rinse, supply of water and discharge of overflow water occur while the water is being agitated. In the water reserve rinse, the water is not supplied while the water is being agitated.
As described above, in the case of the washing machine incorporating the microcomputer-based control circuit, the operation cycle of the washing machine is precisely controlled and the washing machine provides convenience in actual use. However, there are several problems to be solved. First, many switches are provided on the operation panel of the washing machine, so that the number of parts to be assembled is increased and the assembling work becomes complicated. Consequently, production cost of the washing machine is increased. Second, an operator is forced into troublesome switching operation when a desired wash or rinse mode is selected. For example, in the selection of the "TWELVE MINUTES" wash mode, since the "TEN MINUTES" wash mode is selected when the control circuit is initialized, the operator is required to operate the wash mode selecting switch five times to select the "TWELVE MINUTES" wash mode according to the order of selection. In the case of the selection of the rinse mode, the operator also meets such troublesome operation of the rinse mode selecting switch as in the selection of the wash mode. Third, the washing machine is provided with a clear switch for clearing the selected operation steps to reselect a new step. When the clear signal is supplied to the control circuit while the washing machine is being operated with a motor for wash operation running, the control circuit is adapted not to clear the step, thereby preventing the motor from undergoing sudden change in control. However, the clear action is performed if the control circuit is initialized after electrical power is supplied to the washing machine or after the operation cycle of the washing machine is completed. Consequently, for example, when the operator wants to change the action courses from the course including the wash and rinse steps to the course including only the wash step after the operation of the washing machine is started, the operation course is not cleared even if the operation of the washing machine is momentarily interrupted to clear the operation course. To avoid the above-described case, the power-supply switch is usually turned off and then turned on to thereby return the control circuit of the initial condition again. Thus, the operator is forced into troublesome operation of the switches.